Electric-arc lamp.



B. MONASGH.

ELE'GTRIG ARC LAMP.

APE'LIOATION FILED H1120, mos.

Patented Apr. 6, 1909.

- .BVSZE EEHZHULZJMUZVAS'E'B". BY a? A T T? uNrTEnsrAr egigrENr OFFICE.-

BERTHOLD MONASGH, or BERLIN, GERMANY, Asslciion TO GENERAL ELECTRICCOMPANY,

A CORPORATION or NEW YORK.

ELECTRIC-ARC LAMP.

Specification of Letters (Patent.

' Patented April 6, 19.09.

Application filed February 20, 1908; Serial No. 416,827.

terial that is both a good conductor of heat and electricity, is used inconjunction with a .negative' electrode (cathode) whose arcing point isa'conductor of the second class, that is to say a material that is apoor conductor, of electricity in the cold state, but becomes a 'goodconductor when heated.

The object of the invention is to provide means for starting the lamp byheating the arcing point of the cathode by an auxiliary arc untilitbecomes sufficiently conducting to allow a sufiicient current to passbetween it and the anode to strike and maintain an are between them. Avariety of arrange; ments have heretofore been suggested for theaccomplishment of this purpose, but all of them, so far as I am aware,the auxiliary are heated the arcing point of the cathode by contact orclose proximity thereto, and this resulted in the partial disfigurementor destruction of the cathode envelop at or near the arcing point. By myinvention this, and

- other inconveniences of the devices and prac-i tices oi the prior artis avoided, by causing the auxiliary arc to heat the arcing point of thecathode neither by direct contact nor by close proximity, but byconduction through the body of the anode.

' One of the numerous constructions which may be employed in accordancewith my invention is illustrated in the accompanying drawing, which is adiagrammatic represe11- tation of an arc lamp structure and itscircuits.

The anode 1 is here shown as a rather wide er orother metal or substancethat is a goo conductor of heat and electricity; its general form is ofno consequence,,it may be cylindrical or prismatlc.

the lamp, whilethe cathode 2, mounted in a holder 3, which is connectedby a rod .4 with the core 5 ofa solenoid 6, is movable toward and awayfrom the anode. The core 5 is connected to a weight 7 bya' cord or chain8 joined to the This anode is a fixed, element of which passes over afixed pulley 9'. The weight 7 is sufiiciently heavy to raise the corewithin the solenoid, and with it the cathode, into contact with theunderside of the anode when the solenoid is not energized or is notsufiiciently energized. Any 'othermeans may be employed for holding thecathode in .contact with the anode. when no current passes between themand through the solenoid, or when the passing current is lIlSllflicientto energize the solenoid to actuate the core or to maintain an arcbetween the electrodes.

An auxiliary electrode 10, which may be" and preferably is made'ofcarbon, iscon nected by a rod '11 with the core 12 of the solenoid 13,and the combined weight of the core 12, rod 11 and auxiliary electrode10 holds the latter in contact with the, upper face of the anode 1, whenthe solenoid 13 is not energized, or is not sufficiently energizedto'lift the core 12. i The positive lead 14 is connected with the anodeand the negative leadwith one .ter minal (in the case shown, withthelower terminal) of solenoid 13. The other terminal of solenoid 13isconnected bya conductor 16 and resistance 17 with one terminal ofsolenoid 6, the other terminal of which #is joined with rod 4 by aflexible conductor 18.. The solenoid 13 is tapped at an a propri'atepoint 13 by a conductor 19 Whic through a resistance auxiliary-electrode10. The operation of a lamp thus constructed in obvious. When no currentpasses the solenoids do not act upon their cores, and these will assumethe positions shown in the drawing, and botht cathodes, the normalcathode 2 and the auxiliary cathode 10, will be in contact with theanode 1, but with op posite faces of the same. When current is 20 andflexible connection 21, is I started, and if at that moment the coldarcingpoint of the cathode'is not conductive, or J lion'lg and he lowerPart of solenoid 13." oid 13 to lift its corei d'th the aux I Thiscurrent'will sufficiently energize s'olenil-iary electrode to start anarc between the latter and the upper face of the anode. Thisquickly'heat the copper or I auxiliary arc W1 and the latter will othermetal anode,

" that the main arc will be struck. At the uickly and sufficiently heatthe point of t ecathode'2, to make it a comparatively good conductoriAssoon as this happens, current will flow from the positive lead tothe'anode, cathode 2, arm 3, rod 4, flexible conductor 18, solenoid 6,resistance 17, conductor 16, the whole ofsolenoid l3, and the negativelead. Solenoid 6, being now energized, willac'tuate its core 5 againstthe pull of weight 7, and cathode 2 will thereby be withdrawn fromcontact with the anode, so

same time, the magnetic centerofsolen'oid 13' has been raised, so thatthe 'core 12 "willbe raised higher, and high enough to break theauxiliary-arc. Itwill be. seen that in this manner the auxiliary areused for preheating the main cathode does not play about that cathode,so that-the arcing point of the are not disfiguredor destroyed. Insteadof breaking the auxiliary are by same or the sides oflit near the arcingpoint fraising-the auxiliary electrode beyond the arcing distancefromthe anode, it is practicablev to break the auxiliary arc-circuit atany point. of the connection between the auxiliary electrode and thepoint 13 this may he effected b a'switch actuated mechanically or electrcally when the arcing point of the cathode has become sufficientlyconduct ive by preheating.

- by Letters Patent of the United States, is,

1. In an arc lamp, the'combination of an anode that is a good conductorof heat inter-v posed between. a cathode whichis'a conductor of thesecond class and an auxiliary cathode,

means formaintaining contact between the anode and-the cathodes when nocurrent is heating the main cathode b passing through the lamp, meansfor separating the auxiliary cathode from the anode to establish anauxiliary arc and thereby conduction through the anode, and means orstarting an What I- claim as new "and desire to secure are between theanode and the main cathode and furtherseparating the auxiliary cathode-main cathode is heated to electric conduc tivity by heat conductionthrough the anode, and means for starting the ntain are when the 'inaincathode has become sufficiently conductive and further separating theauxiliary cathode to break the auxiliary arc.

3. In an arc lamp, the combination of a mainv cathode that is a' poorconductor of electricity in the cold state, an auxiliary cathode that isa good conductor of electricity in thecold state, a fixed metal anodeinterposed between the two cathodes, means for establishing contactbetween each cathode and the anode when no current is passing throughthe lamp, means forseparating the auxiliary cathode from the anode toestablish an auxiliary are when sufficient current is admitted to thelamp and thereby heating the main cathode by conduction of heat throughtheanode, and means for striking an when the former has beensufiiciently heated to become conductive and thereafter furtherseparating the auxiliary cathode from the anode to break the auxiliaryarc.

In testimony whereof, I have hereunto set my hand this 31st day of January, 1908.

, "BERTHOLD MONASCH. Witnesses: r

JULIUS RUMLAND, ALFRED WOLF.

are between the main cathode and the anode

